Note: Descriptions are shown in the official language in which they were submitted.
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Back~ _nd the Invention
This invention rela~es to a radial bearing apparatus
for a high thrust trolling motor.
In the art of trolling, small electric driven outboard
S motor ~mits are mounted to the transom of a boat and employed for
slow speed maneuverability and positioning of the fishing boats.
The electric drive motor i.s housed within the lower mit and
coupled to drive a suitable propeller. The electric trolling
motor unit may be specially employed in bass fishing and the
like where the motor unik is primarily employed for limited
maneuverability within a fishing area to properly locate t'ne
boat with respect to and positioning of the fisherman's lines.
The motor unit is turned for steering of the boat by a foot
control coupled by push-pull cables to a turning gear means in
lS the head o~ the motor unit and the speed is similarly controlled
from a foot control connected in circuit with a battery and the
motor. A separate high powered internal combustion outboard
motor is normally provided for rapid propulsion of the water~
craft to the fishing loca~ion or spot after which the ~rolling
motor is employed. A particularly unique and satisfactorY motor
unit construction is illustrated in the co-pending Canadian -
application of Charles F. Alexander, Jr., Serial No. 259,669,
entitled "HIGH ~HRUST TROLLING MOTOR" which was filed on August
23, 1976, and assigned to the same assignee.
As more fully disclosed therein, the trolling motor
includes a lower unit within which an electric motor is housed
and coupled to a separate propeller drive shaft by a reduction
gear means to establish a low speed and high torque to turn a ~-
large propeller that produces high thrust. By increasing the
diameter of the propeller unit an increase in the static thrust
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is obtained for a given motor hor~epower. ~le gear reduction
means is a planetary gear system which is uniquely adapted to
practical implementation in a low cost trolling rnotor. The
planetary gear system uniquely dis~ributes the load between
the planet gears. Consequently, relatively inexpensive plastic,
and sintered gear members can be employed. The planetary gear
system is formed as a separate self-contained uniLt of subassembly
to close the corresponding end o~ the lower unit with a convenient
coupling between the propeller shaft and the motor shaft. The
` 10 addition of the gear subassembly increases the overall length
of the lower unit which is therefor constructed as a compact unitO
This invention relates to a trolling motor having a
gear reduction means coupling an electric motor ~o a propeller
shaft and particularly to bearing support means for establishing
accurate alignment of the propeller and water shaft means~ In
accordance with the present in~ention, a radial bearing means -
supports the propeller shaft and includes a spherical seat means.
The gear means includes an output gear secured to said propeller
shaft. The spherical support means establishes proper alignment
of the propeller shaft~
In a particularly unique embodiment of the present
invention, the gear reduction means includes a housing which is
secured to a motor housing. A planetary gear system ~is mounted
wlthin the separate gear housing. The gear system includes a
planetary gear cage secured to the propeller shaft which is
rota~ably suppor~ed within the gear housing by a radial bearing
j which is rotatably supported within the gear housing by a radial
bearing means having a spherical support means to produce proper
alignment of the shaft. In accordance with a further novel
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feature of the preferred embodiment of the invention, the sun
gear is mounted in alignment with the propeller shaft and
includ~s a rotor shaft coupling openlng. The housing includes
a motor shaft opening aligned with the coupling opening. A
radial bearing including a spherical support means is provided
to support the motor shaft in coupling engagement with the sun
gear when the gear housing is secured to the motor housing.
The present invention has been found to provide a
simple, reliable means of establishing and~maintaining the
proper coupling and alignment of the motor and propeller shaft
; means in the lower unit of an electric trolling motor apparatus.
Applicant has found that the shaft bearing assembly
applied to the trolling motor results in a compact construction
which properly supports the shafts in alignment with the gear
reduction means
The drawing furnished herewith illustrates a preferred
construction of ~che present invention in which the above
ad~antages and features are clearly disclosed as well as others
that will readily be understood from the fo310wing description .
In the drawing:
Fig. 1 is a side elevational view of a trolling motor
attached to ~he mounting deck forming a part of a watercraft,
not shown;
Figo 2 is an enlarged side elevational view of the
lower units with parts broken away and sectioned to illustrate
the construction of one embodiment of the present invention;
1 Fig. 3 is an enlarged view taken generally on line 3-3
i o Fig. 2; and
Figure 4 is a vertical section taken generally on line
4-4 of Flg. 3.
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~ _ odlment
Referring to the drawing and particularly to Figo 1
a trolling moto~ l, particulaFly àdapted for bass fishing and
the like, is illustrated mounted to a h~ri~ontal support wall 2
; which will form the appropriate deck or mounting means of awatercraft~ not shown. Generally watercraft for bass flshing
includes a forward deck 2 to which the trolling motor 1 is
pivotedly secured by suitable pivot assembly 3 or selective
positioning of the motor in propelling position shown in Fig. 1.
The assembly 3 permits positioning in a raised alternate position
lying on the deck 2. Generally the trolling ~otor 1 includes a
lower unit 4 within whlch a small electric motor 5 is housed
and coupled to drive a propeller unit 6. The lower unit 4 is
secured to the lower end of a support tube member 7, which may
conveniently be a suitable pipe-like member. S~pporting pipe 7 :
is suitable rotatably journalled or mounted in a swivel tube ~
support 8 which terminates at the upper end within a steering ~ -
housing or head 9. The swivel tube 8 is connected to ~he pivotal
mount assembly 3. me motor 5 is selectively energized from
within the boat 2 to vary the speed of propeller 6 and thereby
the propulsion forces and the trolling motor 1 is pi~oted within .
~ the swivel tube 8 from within the boa~ support to turn the
wat~rcraft. Generally, suitable foot control means are employed
and are diagrammatically illustrated including a speed control
foot UDit 10 connected in circuit with a battery 11 and suitable
connecting leads lla which extend through the upper head 9 and
do~n through the conduit or pipe 7 to a suitable control circuit9
not shown~ for energi~ing of the motor 50 Similarly, a positioning
foo~ control 12 is connected by a push-pull cable 12a to the
upper head 9 within which a suitable rotating gear system 13
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or the like couples the push-pull cable 12a to the upp~r end
of pipe 7, which terminates within housing 99 for selective
rotation thereof. In the Illustrated embodiment of the
- invention, the motor 1 is also provided with an upper handle
14 for selective pivoting and positioning of the steering
head 13. The motor 5 is coupled to the propeller 6 through
a special speed reduction gear unit 15, which in the illustrated
embodiment of the invention i5 formed as a separate subassembly
and connected as an integrated end closure to the lower unit 4O
Generally, the illustrated embodiment of the unit 15
includes a cup shaped gear housing 16 having an outer cylindrical
end portion corresponding to the diameter of the motor housing 17
to which the supporting conduit 7 is secured. The opposite end
of the housing 17 is closed by a sui~able nose cone or housing
18. A pair of conYentional clamping bolts 19 extend through ~he
several housings 16 - 17 and thread into the housing 18 to draw
the several houslng members into firm abu~ting and clamped
~, engagement. O~ring seals 19a are located between the abutting
`, housing sections to ~reate~a liquid tight enclosure of the
motor and associated equipment. The subassembly and particularly
the cup-shaped gear housing 16 further includes a coaxial end
hub 20 within which a propeller shaft 21 is rota~ably mounted.
The hub 22 of the propeller 6 telescopes over the shaft 21 and
-~, is locked in position by an outer locking nut 230 A pin 24
extends through the shaft 21 and into an appropriate recess in
the propeller hub 22 to further interlock the hub to the shaft
for ro~ation of the propeller 60
The inner end of the shaft 21 terminates wlthin the
:~ subassembly 15 and is connected by a reduction gear means or
train 25 ~o the motor shaft 26 which extends from the motor 5
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ancl into the subassembly 1.5 wi~h a releasa~le slip-type inter-
connection to the reduction gear tra:i.n 25.
The gear train 25 is illustratecl in a preferred
embodiment as a planetary gear means and includes a rotating
planetary gear cage 27 which is pinned or o~herwise connected
to the shaft 21. A plurality of planetary gears 28 are rotatably
mounted in meshing engagement with a fixed annulus gear 29 and
an inner sun gear 30 to which the motor shaf~ 26 is coupled..
The planetary gear system is uniquely adapted to the present
application because it provides a highly efficient and long life
with a relati~ely large reduction ratio. For example, in a
practical application employing a three-inch housing, a reduction
ratio of 4.2 to 1 is obtained to thereby significantly reduce
the rotational output and to establish a large torque output
at the propeller unit 6. The propeller unit 6 includes a pair
of broad blades 31 of a long radial extent which convert the high
torque achieved by the reduction gear to high thrust for improved -
~maneuverability of the boat 2
More particularly in the illustrated preferred
embodiment of the present invention, the housing 16 is generally ~:
cup-shaped member with an outer end or base portion including a ;~
reduced diameter hub 20 and an inner cylindrical portion for ;
mating with the cylindrical motor housing 17. The cylindrical
portion of the cup-shaped housing 16 has an inner diameter
sized to receive the annulus gear 29, with such gear abutting
an inner annular planar base surface 20a. The annular gear 29
is c].amped to the surface 20a by a mo~or shaft bearing hub ;~
member 32 having an outer cylinder portion 33 telescoping in
close fitting engagement within the inner cylindrical portion
of the housing 16. Gaskets 34 are disposed to the opposite
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sides of` the annulus ge~ 29 ancl the element;s are clampe~
illtO an integra-ted uni-t by a pair of clamping bolts 35
which extend -through the ou-ter base of the cup-shaped
housing 16, through the gear 29 and the associa-ted gaslcets
3~ and -thread in-to a suitably taped openingcs in the cylin--
drica:l portion 33 of -the hub member 32. The clamping bolts
35 are diametrically located on the assembly and offset
90 from the mounting openings for the motor assembling
- bolts 19, shown in Fig. 2. The cylindrical portion 33 o~
the hub member 32 may projec-t outwardly from the housing
16 slightly to provide a support and guide portion which
projects into the cylindrical motor housing 17 as most
clearly shown at 36 in Figs. 2 and 4. The 0-ring seals l9a
; may be provided at the abutting junction therebetween by a
small recess provided in the inner corner of the housing 16
immediately adjacent the guide portion 33. The annulus gear
29 is thereby rigidly clamped in position as a fixed gear
of the planetary gear train 25.
~l The opposing faces of the cup-shaped housing 16 and
the hub member 32 are recessed to define a gear chamber
within which the planetary gear train 25 is disposed. In
particular, the sun gear cage 27 is located within a suitable
recess in the cup-shaped housing 16. The cage 27 is shown
as!a disc-like plate coaxially aligned with the sun ~ear 30
with the three planetary gears 28 secured to the cage in any
suitable manner as by staking or rivets 37 to rotatably sup-
i port the planetary gears in meshing engagement with the ann-
`~ ulus gear 29 and with the sun gear 30. The sun gear 30 is
a conventional small circular gear member which mates with
the several planetary gears 28 and in the illustra-ted embodi-
s men-t is particularly formed with a central stepped opening
~ 38 which is adapted to receive
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the inner end o~ the motor shaft 26 which ls correspon~ingly
shaped.
As most clearly sho~n in ~igs. 3 and 4 ? the opening
38 and -the ou-ter end of the mo-tor shaft 26 are similarly
formed with keying portions in -the form o~ an of-fse-t chor-
dal loclcing or keying flat surface 38a providing rotational
interlock of the sha-~t 26 to the sun gear 30. 'I'he inner
end of the opening 38 is shown closed by a thrust washer
39 which abuts a bearing means 40 on the adjacen-t surface
of cage 27. In the illustrated embodiment, the inner end ;~
of the propeller shaft 21 projects inwardly slightly from
the face of the cage 27 and is rounded to present a bearing
surface 40 to the washer 39. In the assembled relation,
such gear 30 is held firmly on the shaft 26 and is coupled
thereto by the offset drop opening 38 to transmi-t the out~
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put of the motor 26 through the planetary gear system 25
to the propeller shaft 21. The rotation of the small sun
gear 30 results in the rotation of the planetary gears 28
about their own axis, with the meshing with the fixed
annulus gear 29 generating a rolling movement thereon aboutt
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the axis of the sun gear 30 in accordance with well-known
functions. The rotary motion is transmit-ted -through the
cage 27 to the propeller shaft 21 and thus -to the propeller.
In the illustrated embodiment of the invention, the
propeller shaft 21 is ro-tatably supported within the hub
20 by a single spherically mounted thrust bearing 41 secured
within an outer recessed hub portion. The spherical support
of -the single radial bearing as illustrated insures that
the propeller shaft and the attached planetary gear dage
and gears may properly align with the gear system and parti- -
cularly the annulus and sun gears in the illustra-ted embodi-
ment. The outer end of -the hub is
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sealed by a pair of suitab:Le rotary sea:Ls ~Z o~ any
desired or sui-tab]e construct:iorl. ~s such e~Lernen-ts are
well-known and can be readily provided by the ordinary
worker skilled in -the ar-t, no further description is
given.
Similarly the motor shaf-t hub member 32 is recessed,
with an outer spherical bearing 43 and an inner ro-tary
seal 44 located immediately adjacen-t to -the gear chalnber.
The opposite end of the motor sha-~t Z6 may be similarly sup-
ported by a sealed spherical bearing assembly 45 clamped
between the opposi-te end o~ the housing 17 and the nose
cone housing 18 as at 46.
In the assembly, the planetary subassembly 15 is
constructed with the clamping bolts 35 developing an inte-
grated structure. The assembly 15 is dropped over the
mo-tor shaft 26, and i~ necessary, slowly rotated to
align the offset interlocking chordal portion 38a with the
corresponding ~lat porti~n of the shaft 26 such that the
assembly will drop into in-terlocking engagement. The
assembly bolts 19 are then inserted and drawn up tightly
wi-th the thrust washer 39 o~ the sun gear 30 moving into
bearing relationship with the inner end o~ shaft 21 to com-
plete the assembly o~ the lower unit for receiving of the
propeller unit 6. The hub 22 of propeller unit 6 can be
dropped onto -the assembled unit with the pin 24 aligned
with the connec-ting recess and clamping nut 23 tightened
to complete the assembly.
The present inven-tion thus provides an improved
sha~t bearing support permi-tting a compact gear coupling
means for an electric -trolling motor.
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